Piston ring



Feb. 21, 1933.

s: TYDEN PISTON 31m Filed Feb. '26. 1952 2 Sheets-Sheet 1 jhde/zfoz".

I ma'Z '1 E. TYDEN PISTON RING Feb. 21, I933.

x r x w #0 m j v Filed Feb. 26, 1932 2 Sheets-Sheet 2 jmd e 72 237? Emaljja Jim crank; case.

Patented Feb. 21, 1933 [*UNITED STATES PATENT OFFICE mm. Trimmer nas'rmos, EICH-IGAN 'rrs'rou nnve Application filed February 28, 1982. Serial No. 595,258.

The purpose of this'invention is to provide an improved piston ring suitable for use in an internal combustion engine, but not limited to such engine, adapted to be eco- 5 nomically produced and to function for properly distributin the lubricating 011 over the path of stro e of the piston in the cylinder, and to afford drainage for the surplus oil through the piston to the engine elements and features of construction of the ring and the method of producing the same shown and described as indicated in the claims.

In the drawings: a

Figure 1 is an axial section of an engine cylinder having a vpiston equipped with a rmig embodying this invention.

' igure 2 is a plan view of one of the piston rings embodying the invention.

Figure 3 is an edge elevation of the same looking in the direction of the arrow 3 on Fig .ure 2. a

Figure 4 is a section at the plane indicated by the line 4-4 on Figure 3.

Figure 5 is a viewsimilar to Figure 4 showing the drainage apertures reduced in dimension as com ,ared with Figure 4.

Figures Gand are diagrammatic views of mechanism'which may be used in roducing the ring shown in the preceding figures.

Figure 8 is an edge elevation looking in the direction-of the arrow 8 on Figure 4.

Figure 9 is -a view similar to Figure 4 of a modified form.

I Figure 10 is a detail edge elevation of the form shown in Figure 10 looking in the directon of the arrow 10 on Fi re 9.

Figure '11 is a detail edge elevation of the form shown in Figure 9 looking in the direction of the arrow 11 on Figure 9.

Before proceeding with description of the construction in detail to assist in the understandin of said construction and the purposes o. the difierent details, the specific urposes of the invention may beset fort as follows:

A purpose of the invention embodied in the ring shown in the drawings is to adapt Theinvention consists in the tween the opposite transaxial "faces 0 to afford reservoirs. in which the oil is carried by the ring for distribution over the cylinder wall in the piston stroke, and also to provide means by which oil in excess of that which is required for proper lubrication may be drained through or past the ring into the piston grooves, and thence through the drainage ports of the piston into the hollow piston cavity for passing back to the crank case.

In ca u out these rimary pu case the cons t i' iiction of the rihg is desigh ddtd afiord means for uniform distribution of the oil circumferentially of the ring and piston groove.

Another purpose of the invention is to provide a ring of desired rigidit which is effected by having the outer we 3 tied t0- gether by a num er of radially staggered ridges, or supports preventing the rin from collapsing or expanding, either througii the strains set up in manufacturing, such as forcin a dull cutter into the metal and spreading the sides of the ring as chap us when the cut is entirely through the wail of the ring or from the strains of friction on due tothe heat of the motor. I

A further purpose is to efiect distribution of the breaking'strain, due to spreading the ring in introducing it over the end of the piet'on, over a substantial arcuate. extent of the ring, avoiding concentration of the strain at the point opposite the split.

A further and important purpose of the invention is to render the ring economical in production by customary shop methods.

For accomplishing these purposes, the rin indicated in its entirety by reference numerafi 30, is formed with a series of recesses, 31, which may be as shown, eight in number, cut in the outer circumference of the ring he the ring, the consecutive recesses being spaced apart a short distance, as indicated at 33.

These recesses made by saw out, as hereinafter the cylinder walls as well 'as the expansion the inner recesses are s at? described, are in radial depth substantially less than the radial width of the ringand of uniform depth throughout their circumferential extent except that at the opposite ends. the bottom of the recesses are sloped outward radially due to the use of a revolving circular saw cutter by which the recess is cut.

In the inner circumference of the ring is formed a similar circumferential inner series of recesses, 35, cut from the inner side and extending radially outward to a depth of at least equal to,-and preferably slightly more them-the difi'erence between the radial width of the ring and the depth of the first mentioned recesses. These recesses, 35, similar to the recesses, 31, are of uniform depth throu hout their circumferential extent, except t at at the opposite ends the bottoms of sloped radially inward at the end portions, due to the use of the rotating cutter by which the recesses are cut.

The recesses, 35, of the inner series are positioned respectively radially opposite the intervals and partitions between t e recesses, 31, of the outer series, staggered relation; and each dimensioned circumferentially, that is, as to length, for lapping at opposite end portions on the proximate end portions of the adjacently consecutive recesses of the outer series.

It will be noted that by reason of the lapping upon each other of the end portions of the corresponding recesses of the two series, apertures seen at 36 are produced, through which the recesses of the two series have flow communication with each other; and that by reason of the lapping described, with the communication apertures resulting at both ends of each of the recesses of both series, the two series of recesses together constitute a completely continuous flow passage entirely around the ring, which serves the purpose of permitting the oil which may be abundant at one part of the circumference of the piston and cylinder, and deficient at another part, to flow around the piston and to supply the deficiency. It will be noted that as shown in the drawings the extent of lap of each of the inner and outer recesses is relatively short, so that the apertures are relatively restricted, thereby adapting the construction to operate limitedly for drainage of oil through the hollow piston to the crank case, while affording I adequate facility for circulation around the piston for equal distribution of the oil, as described.

The method of production of rings of the k construction shown constitutin part of the present invention will now be escribed.

The rings, 30, of suitable material dimensioned for being accommodated in the piston grooves, are first produced in the usual manner without the recesses described; and for forming these recesses, the ring, 30, may be mounted fast on a mandrel, 40, and subjected and thereby in radially v scribed, it ma to the action of a rotating cutter, 41, which is mounted for being advanced radially against the outer circumference of the ring in a plane intermediate the planes of the opposite transaxial faces of the ring, the thickness of the cuter blade being to a substantial amount less than the thickness ofthe ring. The mandrel is arranged to be adjusted angularly about its axis to set the rin successively at the different positions suita le for exposing toward the cutter blade successively the areas of its circumference which are to receive the circumferentially successive recesses respectively, the revolving cutter blade, 41, havin its shaft, 42, journalled in an arm, 43, whic is pivoted at 44 to an arm, 46, the latter arm bein pivoted for swingin about the axis of t e mandrel, 40, as in icated diagrammatically in Figure 6. To roduce the recesses of the outer circum erential series, the operator at each an ularly adjusted position of the mandrel an ring swings the cutter blade inward radially with respect to the mandrel and ring thereon to the proper distance for cutting the recesses of desired depth as described, and then swings the cuttercarrying arms, 43 and 46 about the mandrel axis through an are for cutting the recesses of the desired arcuate extent, the line a-a in Figure 4 showing the approximate path of the center line of the cutter in relation to the ring. 7

For forming the recesses of the inner series, the rin may be mounted in a chuck or holder in icated by the carrying arm, 50, in Figure 7 said holder being mounted for adjustment angularly about its axis to position the ring at the several positions suitable for exposing the successive arcs of the inner circumference of the ring at which the recesses of the inner series are to be formed to the radial attack of the revolving cutter blade indicated at 51, which it may be understood is mounted for swinging outward for thus attacking.the inner circumference of the ring, and forming the recesses of the inner series of the desired arcuate extent, the dotted line b-b in Figure 4 showing approximately the path of the center line of the cutter in relation to the ring.

Upon considering the operation of the piston ring constructed and mounted as de be recognized that in the stroke of the piston, the recesses of the outer series will collect the oil scraped or wiped from the cylinder wall; and that the oil thus accumulated being free to pass from the recesses of the outer series into the successively adjacent recesses of the inner series, and from the latterto pass back into the next of the successively adjacent outer recesses, it results that thus the oil scraped from the cylinder wall at one side where the oil is abundant,-

may be transferred to any part of the cylinder wall where it is deficient.

sent thin edges for scraping or wiping the oil And upon further consideration it may1 be recognized that some part of the oil w ich passesftheapertures, 36, willremain in the recesses of the inner series, and thereby in the piston groove, and eventually may be drained out through the ports of the hollow piston into the crank case.

Upon'further consideration it will be rec ognized that the apertures,,36, being rendered acute-edged b the sloping of; the lapped end portions iof 't ebottomsof'the recesses of the liability of clogging is further reduced 7 by these apertures being not at the inner circumference of the ring, but at a position leaving circumferential clearance between the apertures and the bottom of the. piston grooves.

Upon considering the function of the pis ton ring for scraping or wiping the oil from the c linder wall, it may be recognized that its e ciency for this function is promoted by the presence of the recesses of the outer series, these recesses being in width so large a fraction of the entire thickness of the ring that the lateral walls of the groove constituting peripheral circumferentially continuous anges, as seen at 39 are quite thin and preas described.

And upon this consideration it may be recognized as desirable that this feature of thin edges should characterize the entire circumference of the ring without interruption at any part, except where such interruption may be required in some cases to add strength to the ring, as for example and particularly at the point diametrically opposite the gap and at the ends at both sides of the gap.

For these reasons the ring is made, as shown in Figure 3, with the partitions, 33, between the consecutive recesses, 31, cut

away at their outer circumferential ends to a very slight amount, as seen at 38, leaving standing only lateral portions which render the scra ing edges of the ring circ1nnferen tially su stantially continuous.

Upon considerin the construction resulting from reducing t e partitions as described so that there is flow communication between consecutive pockets over the radially outer end of the partitions, it will be recognized that by this means the pockets are rendered component parts of a circumferentially continuous flow passage around the rin In Figure 9 there is illustrated a modifi'e form of the invention embodying this characteristic.

, ,In this modificationthe outer series ofrecesses, indicated at'33", are identical in form and relation to each other with the recesses,

33, of the form shown in the previous figures,

but the recesses,v35", ofthe inner series are less in radial'depth than the diiierence between the'radial width of the ring and "the depth of the recesses,33, of the outerseries; so that the lapping past each other. of the end portions ofthe respectively adjjac en't recesses of the two series does not create an, aperture for flow communication between the j lapped recesses. 'And a'ccordingly inthis form, Figure 9, the communication for flow radially of the mug 1n either "direction 1s provided for by apertures-indicated at 35 which are cut through the web left stand-' ing between the lapped portions of the outer and inner recesses respectively.

I claim: Q 1. A piston ring having an external circumferential series of recesses circumferentially spaced apart, eachxtending inwardly from the outer circumference of the ring to a depth substantially less than the radial width ofthe ring, and a second internal series of recesses extending from the inner circumference of the ring outwardly to a depth at least equal to the difierence between the dc th of the first'mentioned recesses and the ra ial width or the ring, the individmilsoi said second series of recesses being circumferentially spaced apart successively and being each radially opposite the interval bethe first series and having their end portions lapping the end portions ct said individuals of the first series, the recesses of-both series tit tween two consecutive individual recesses of having their bottoms at" the opposite end portions thereof sloped and having the laps exceeding the length'of the sloped portions and including a portion'of the co-axially curved intermediate part of the bottoms of both series of recesses, whereby said lappin portions constitute apertures through whicn the lapping recesses "open into eachcther, and the ends of said apertures are rendered acute-edged and the radial extent of the apertures constituting flow passages intermediate the inner and outer circumferences of the ring is made substantially zero.

2. A piston ring having aseries of external recesses each extending inwardly from the outer circumference of the ring a dis tance substantially less than the radial width of the ring and a series'of spaced internal recesses each extending outwardly from the inner circumference of the ring a distance substantially less than the radial'width of the .ing inwardly lation to said external recesses,'said internal and external recesses being connected at their ends by relatively small apertures disposed in substantially spaced relation to the inner edge of the ring, the portions offthe'edges' of the ring between the recesses beveled to thin-edges. I

- {3. A; piston ringhaving a"'series'"of uniformlyspaced external each extendfrom the outer circumference of the ring a distance' substantially less than the radial width of the ring, andaserie's Qfspaced internal rece e hextending outwardly from the inner circumference of 7 the ring a distance,substantigl1y1 .v 7

oi bothwseries have radial flow communication; with each other, the ring'being radially extended throughout its entire circumferenceat both transaxial sides slightly beyond the circumferential intervenin par-' titions to form relativelyfthin-edged anges at both sides for wip n jthe .w'auef the en- 'ne' cylinder! in- ,the proper strokes of the piston. n. Intestimon whereoi, I'have hereunto set my :hand at astings, Michigan, this 19th day of. Februa ry,,1932. t r' I radial width of the ring disposed in alternat ing overlappingvrelation -to said external resaid internal cesses their ends by relatively ing connected at small apertures and external rece e b 2 disposed in substantially V spaced relation to the inner edge ofthe ring.

4. A piston ring havingaseries of uniformly spaced external recesses eachextending inwardly thering a distance substantially less than from theouter circumference of the radial width of the ring areats by Y relatively shallow external grooves,'- and series of spaced internal recesses each extendmg outwardlyfrom the inner circumference substantially less than in al-' of the ring a distance the radial width of the ring disposed Lternating overlappingrelation to said ex" ternal recesses, said internal and external recesses being connected at their ends by relatively small apertures disposed in substantially spaced relation to the inner 'edge f i the ring.

- 5. A piston for an internal'combus tion engine having an external circumferem the sametial series of consecutive recessesin transaxial plane between the opposite trans- ,axially extending sides of the ring, the 'c'onsecutive recesses of the seriesibeing clrcumferentially spaced apart from eachother a relatively short distance by intervening par.-

titions and having the opposite end portions 1 of their bottoms slopedin'amanner render transaxial plane each individual having its'oppo- 1 "site end portions lapping proximate end por recesses deeper at the inter ed '7 .Q

of their length, thede'pth t' circumferential tions of two consecutive recesses of the'first mentioned. series, the radial depth of the grooves of the last mentioned series being substantially the ring and ference between of the ring, whereby less than the radial width-ofbein'gat least equal'to the dif-' the radial depth of the rev 'cesses of the first series and therad-ial width the lapping of said recesses produces apertures through which the its 

